1. Field of the Invention
The present invention relates to an electrophotographic device fen which a main body is formed of a lower body and an upper body such that a photosensitive drum is easily replaced.
2. Description of the Related Art
In an electrophotographic device, a photosensitive drum will inevitably deteriorate as it is used, and thus must be replaced with a new one every predetermined period of time. Therefore, the photosensitive drum is mounted in the device such that the drum can easily be detached therefrom. In general, to facilitate replacing of the photosensitive drum, the main body is formed of a lower body mounting the photosensitive drum and a swingable upper body. When the upper body is opened, a used photosensitive drum is detached from the lower body and a new photosensitive drum is mounted therein.
With this structure, the photosensitive drum is easily displaced from a regular position. Displacement of the drum relative to the upper and lower bodies may adversely affect the quality of image. For example, such displacement may cause a driven gear secured to the drum, to be wrongly meshed with a driving gear for transmitting a driving force generated by a motor mounted in the lower body to the drum, inducing unstable rotation of the drum. As a result, jitter appears on the image. Further, a light beam emitted from an exposure unit mounted in the upper body cannot be exactly focused on the surface of the drum due to the displacement of the drum. This results in blurring of the image.